The invention relates to an apparatus for feeding sheets seriatim from a stack of sheets and, in particular, to an apparatus for buckling and separating a sheet from a stack of sheets in order to feed one sheet at a time.
In most printing, duplicating, and mailing machines, there is an apparatus for feeding sheets from a stored sheet stack into the machine for further processing. The process for removing a sheet from a sheet stack is called singulation. The prior art is replete with apparatus for buckling then separating the top or bottom sheet from a sheet stack pursuant to feeding sheets seriatim through an apparatus, but suffer from one or more of the following shortcomings. In some instances, singulators are incapable of handling sheets of various thickness. In other instances, glossy coated sheets are very difficult to singulate because the sheets have a tendency to stick together. This is believed to be caused by inter-sheet frictional forces that are influenced by such ambient factors as temperature and humidity, as well as by inherent factors, such as the sheet finish, the type and grade of the sheet, and the mechanical properties of the sheet. Most feeders that deliver glossy paper singulate using air and/or a vacuum sheet feeder to separate each sheet from a stack of sheets. These systems are expensive, noisy, and thus ill-suited for use in an office environment.